1. Field of the Invention
This invention pertains to waste traps for sewer lines to prevent foreign objects from passing into sewer line systems thereby clogging same.
2. Description of the Prior Art
The prior art disclose devices which are positioned in sinks or toilet bowls and function to catch debris and prevent same from entering the main discharge line. Representative of the prior art are the following patents.
______________________________________ Patentee U.S. Pat. No. Issue Date ______________________________________ H. M. Lehmann 2,693,603 Nov. 9, 1954 H. Hoffman et al 2,785,561 March 19, 1957 D. C. Beer 3,268,920 Aug. 30, 1966 Walraven 4,301,557 Nov. 24, 1981 Halstad 4,307,476 Dec. 29, 1981 ______________________________________
Lehmann (U.S. Pat. No. 2,693,603) is a device comprising an expandable ring and hook arrangement. The device is placed in the outlet channel of a toilet bowl and the hook functions to snag washcloths and the like which are inadvertently dropped into the toilet bowl. The disadvantage of the Lehmann device is that it also snags paper products which are normally disposed of in toilet bowls. A further disadvantage of Iahmann is that it will not snag or catch solid objects such as containers. In addition, the hook portion will rust in a short period of time and the device must be removed and a new one replaced.
Hoffman et al (U.S. Pat. No. 2,785,561) is a screen for use in toilet bowls and it functions to support soiled articles such as diapers which are rinsed by flushing. Beer (U.S. Pat. No. 3,268,920) is a waste trap device which is used in bath and basin waste lines thus preventing same from becoming clogged. The device is comprised of a series of arks having a plurality of inwardly extending triangular portions having upstanding spikes and barbs. The disadvantage of this device is that it is too fragile to be maintained in a main sewer line.
Walraven (U.S. Pat. No. 4,301,557) is a strainer device which is used in sinks and functions to minimize clogging. This device could not be used in a main sewer line as it would prevent the passage of normal paper products.
Halstad (U.S. Pat. No. 4,307,476) is similar to Lehmann in that it comprises a ring having a number of inwardly extending spikes. Further, this device is permanently in place in the outlet channel of a household toilet bowl. The device has the same shortcomings as Lehmann in that the hooks function to snag articles of clothing and heavy paper and will not function to prevent the passage of solid objects such as containers. Moreover, this device is also subject to corrosion after a short period of time which will require its replacement.